Digital communication has revolutionized telephone networks. One particular aspect, Voice over Internet Protocol (VoIP), has provided increased efficiency and quality for real-time voice communications. VoIP utilizes protocols to initiate and control call parameters.
In the VOIP network, a Media Gateway Controller (MGC) performs functions such as session setup, routing of the call, billing, initiation of lawful interception, etc. The MGC is responsible to capture and transmit accurate information related to the call which is relevant for charging of the call to the billing system. The information includes call/session setup notification, call/session teardown notification, bandwidth and media resources used for the call, etc. All these information in turn, would enable the billing system to determine the amount to be charged to the user for the call.
For some reason, if the call is torn down only on the signaling plane i.e., in the MGC and not on media plane i.e., in the Media Gateway (MGW), it could lead to faulty/unauthorized communication, unaccounted resource utilization and results into significant undercharging for the call. This is because the calling and called users will be actually communicating with each other after the call was torn down on the signaling plane.
One of the existing technique is to detect hanging terminations in the MGW by the MGC i.e., media plane terminations that are still active for a call whose signaling plane resources have been cleared. The mechanism also discloses cleaning up of hanging resources in the MGW. However, the periodicity of such resource clean up cannot be too frequent as it may add to the overhead of the MGW, and also adds an overhead on the network traffic. In some cases, the periodicity is set to typically ten minutes or higher, which still fails to resolve the undercharging issue for the faulty/unauthorized communication.
Another technique to ascertain if the media plane resources for a call are still active is by sending a periodic audit request to the MGW by the MGC to know the usage status of media plane resources in the MGW. However, it is impractical to perform frequent audits for all the media terminations in the MGW due to the computation/processing overhead in the MGW and the MGC, as well as the signaling overhead i.e., overhead in network traffic involved. So, the MGC typically requests the MGW to perform an audit for a subset of media plane resources on a rotational basis during each audit interval. An audit interval would be typically an hour, so it may take an hour or longer for auditing the particular media resources that were involved in the faulty/unauthorized communication. So, this mechanism still fails to resolve the undercharging issue for the faulty/unauthorized communication
Even if there are active resources in a faulty/unauthorized communication, it cannot be concluded by the MGW as such whether the user was still engaged in the communication. Further, the duration and resource usage by the users in a faulty/unauthorized communication cannot be determined by the current mechanism in MGW/MGC.
Therefore, the present techniques do not provide for determining whether the calling and called users were involved in faulty/unauthorized communication in a torn-down call. The call information is thus inadequate in the call record for the billing system to arrive at an accurate charging for the call.